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Vester-Christensen MB, Holck J, Rejzek M, Perrin L, Tovborg M, Svensson B, Field RA, Møller MS. Exploration of the Transglycosylation Activity of Barley Limit Dextrinase for Production of Novel Glycoconjugates. Molecules 2023; 28:4111. [PMID: 37241852 PMCID: PMC10223164 DOI: 10.3390/molecules28104111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/03/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
A few α-glucan debranching enzymes (DBEs) of the large glycoside hydrolase family 13 (GH13), also known as the α-amylase family, have been shown to catalyze transglycosylation as well as hydrolysis. However, little is known about their acceptor and donor preferences. Here, a DBE from barley, limit dextrinase (HvLD), is used as a case study. Its transglycosylation activity is studied using two approaches; (i) natural substrates as donors and different p-nitrophenyl (pNP) sugars as well as different small glycosides as acceptors, and (ii) α-maltosyl and α-maltotriosyl fluorides as donors with linear maltooligosaccharides, cyclodextrins, and GH inhibitors as acceptors. HvLD showed a clear preference for pNP maltoside both as acceptor/donor and acceptor with the natural substrate pullulan or a pullulan fragment as donor. Maltose was the best acceptor with α-maltosyl fluoride as donor. The findings highlight the importance of the subsite +2 of HvLD for activity and selectivity when maltooligosaccharides function as acceptors. However, remarkably, HvLD is not very selective when it comes to aglycone moiety; different aromatic ring-containing molecules besides pNP could function as acceptors. The transglycosylation activity of HvLD can provide glycoconjugate compounds with novel glycosylation patterns from natural donors such as pullulan, although the reaction would benefit from optimization.
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Affiliation(s)
- Malene Bech Vester-Christensen
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark; (M.B.V.-C.); (B.S.)
| | - Jesper Holck
- Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark;
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7TJ, UK; (M.R.); (R.A.F.)
| | - Léa Perrin
- Applied Molecular Enzyme Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark;
| | | | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark; (M.B.V.-C.); (B.S.)
| | - Robert A. Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7TJ, UK; (M.R.); (R.A.F.)
| | - Marie Sofie Møller
- Applied Molecular Enzyme Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark;
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Integrative structure determination reveals functional global flexibility for an ultra-multimodular arabinanase. Commun Biol 2022; 5:465. [PMID: 35577850 PMCID: PMC9110388 DOI: 10.1038/s42003-022-03054-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 07/15/2021] [Indexed: 11/08/2022] Open
Abstract
AbnA is an extracellular GH43 α-L-arabinanase from Geobacillus stearothermophilus, a key bacterial enzyme in the degradation and utilization of arabinan. We present herein its full-length crystal structure, revealing the only ultra-multimodular architecture and the largest structure to be reported so far within the GH43 family. Additionally, the structure of AbnA appears to contain two domains belonging to new uncharacterized carbohydrate-binding module (CBM) families. Three crystallographic conformational states are determined for AbnA, and this conformational flexibility is thoroughly investigated further using the "integrative structure determination" approach, integrating molecular dynamics, metadynamics, normal mode analysis, small angle X-ray scattering, dynamic light scattering, cross-linking, and kinetic experiments to reveal large functional conformational changes for AbnA, involving up to ~100 Å movement in the relative positions of its domains. The integrative structure determination approach demonstrated here may apply also to the conformational study of other ultra-multimodular proteins of diverse functions and structures.
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3
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Kim SY, Kim H, Kim YJ, Jung DH, Seo DH, Jung JH, Park CS. Enzymatic analysis of truncation mutants of a type II pullulanase from Bifidobacterium adolescentis P2P3, a resistant starch-degrading gut bacterium. Int J Biol Macromol 2021; 193:1340-1349. [PMID: 34740684 DOI: 10.1016/j.ijbiomac.2021.10.193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 11/28/2022]
Abstract
A putative type II pullulanase gene, pulP, was identified in Bifidobacterium adolescentis P2P3. PulP possesses an α-amylase domain at the N-terminus and a pullulanase type I domain at the C-terminus, as well as three carbohydrate-binding modules (one CBM25 and two CBM41s) between them. The native PulP and four truncated mutant recombinant proteins (PulPΔCΔP, PulPΔP, PulPΔAΔC, and PulPΔA), in which each of the two catalytic domains and/or the CBMs were deleted, were produced in Escherichia coli and their specific properties were characterized. The removal of either catalytic domain abolished the corresponding catalytic activity of the wild-type enzyme. Deletion of the C-terminal domain resulted in a drastic decrease in the optimal temperature and thermostability, indicating that the pullulanase domain might be related to the temperature dependency of the enzyme. In addition, the elimination of the CBMs in the mutant proteins led to a loss of binding affinity toward raw substrates as well as the loss of their hydrolysis activities compared to the wild-type enzyme. HPAEC and TLC analyses proved that PulP and its mutants could hydrolyze α-glucans into maltotriose as their main product. These results suggest that PulP may play an important role in α-glucan metabolism in B. adolescentis P2P3.
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Affiliation(s)
- Sun-Young Kim
- Department of Food Science and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin 17104, Republic of Korea
| | - Hyeran Kim
- Department of Food Science and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin 17104, Republic of Korea
| | - Ye-Jin Kim
- Department of Food Science and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin 17104, Republic of Korea
| | - Dong-Hyun Jung
- Microorganism Resources Division, National Institute of Biological Resources, Incheon 22689, Republic of Korea
| | - Dong-Ho Seo
- Department of Food Science and Technology, College of Agriculture and Life Sciences, Jeonbuk National University, Jeonju 54896, Republic of Korea
| | - Jong-Hyun Jung
- Radiation Research Division, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea; Department of Radiation Science and Technology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Cheon-Seok Park
- Department of Food Science and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin 17104, Republic of Korea.
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Predicting drug targets by homology modelling of Pseudomonas aeruginosa proteins of unknown function. PLoS One 2021; 16:e0258385. [PMID: 34648550 PMCID: PMC8516228 DOI: 10.1371/journal.pone.0258385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 09/24/2021] [Indexed: 11/19/2022] Open
Abstract
The efficacy of antibiotics to treat bacterial infections declines rapidly due to antibiotic resistance. This problem has stimulated the development of novel antibiotics, but most attempts have failed. Consequently, the idea of mining uncharacterized genes of pathogens to identify potential targets for entirely new classes of antibiotics was proposed. Without knowing the biochemical function of a protein, it is difficult to validate its potential for drug targeting; therefore, the functional characterization of bacterial proteins of unknown function must be accelerated. Here, we present a paradigm for comprehensively predicting the biochemical functions of a large set of proteins encoded by hypothetical genes in human pathogens to identify candidate drug targets. A high-throughput approach based on homology modelling with ten templates per target protein was applied to the set of 2103 P. aeruginosa proteins encoded by hypothetical genes. The >21000 homology modelling results obtained and available biological and biochemical information about several thousand templates were scrutinized to predict the function of reliably modelled proteins of unknown function. This approach resulted in assigning one or often multiple putative functions to hundreds of enzymes, ligand-binding proteins and transporters. New biochemical functions were predicted for 41 proteins whose essential or virulence-related roles in P. aeruginosa were already experimentally demonstrated. Eleven of them were shortlisted as promising drug targets that participate in essential pathways (maintaining genome and cell wall integrity), virulence-related processes (adhesion, cell motility, host recognition) or antibiotic resistance, which are general drug targets. These proteins are conserved in other WHO priority pathogens but not in humans; therefore, they represent high-potential targets for preclinical studies. These and many more biochemical functions assigned to uncharacterized proteins of P. aeruginosa, made available as PaPUF database, may guide the design of experimental screening of inhibitors, which is a crucial step towards the validation of the highest-potential targets for the development of novel drugs against P. aeruginosa and other high-priority pathogens.
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Cockburn DW, Kibler R, Brown HA, Duvall R, Moraïs S, Bayer E, Koropatkin NM. Structure and substrate recognition by the Ruminococcus bromii amylosome pullulanases. J Struct Biol 2021; 213:107765. [PMID: 34186214 DOI: 10.1016/j.jsb.2021.107765] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 06/11/2021] [Accepted: 06/23/2021] [Indexed: 01/15/2023]
Abstract
Pullulanases are glycoside hydrolase family 13 (GH13) enzymes that target α1,6 glucosidic linkages within starch and aid in the degradation of the α1,4- and α1,6- linked glucans pullulan, glycogen and amylopectin. The human gut bacterium Ruminococcus bromii synthesizes two extracellular pullulanases, Amy10 and Amy12, that are incorporated into the multiprotein amylosome complex that enables the digestion of granular resistant starch from the diet. Here we provide a comparative biochemical analysis of these pullulanases and the x-ray crystal structures of the wild type and the nucleophile mutant D392A of Amy12 complexed with maltoheptaose and 63-α-D glucosyl-maltotriose. While Amy10 displays higher catalytic efficiency on pullulan and cleaves only α1,6 linkages, Amy12 has some activity on α1,4 linkages suggesting that these enzymes are not redundant within the amylosome. Our structures of Amy12 include a mucin-binding protein (MucBP) domain that follows the C-domain of the GH13 fold, an atypical feature of these enzymes. The wild type Amy12 structure with maltoheptaose captured two oligosaccharides in the active site arranged as expected following catalysis of an α1,6 branch point in amylopectin. The nucleophile mutant D392A complexed with maltoheptaose or 63-α-D glucosyl-maltotriose captured β-glucose at the reducing end in the -1 subsite, facilitated by the truncation of the active site aspartate and stabilized by stacking with Y279. The core interface between the co-crystallized ligands and Amy12 occurs within the -2 through + 1 subsites, which may allow for flexible recognition of α1,6 linkages within a variety of starch structures.
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Affiliation(s)
- Darrell W Cockburn
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Ryan Kibler
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Haley A Brown
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Rebecca Duvall
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Sarah Moraïs
- Faculty of Natural Sciences, Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel
| | - Edward Bayer
- Faculty of Natural Sciences, Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel; Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States.
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6
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Microbial starch debranching enzymes: Developments and applications. Biotechnol Adv 2021; 50:107786. [PMID: 34147588 DOI: 10.1016/j.biotechadv.2021.107786] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 06/04/2021] [Accepted: 06/15/2021] [Indexed: 12/28/2022]
Abstract
Starch debranching enzymes (SDBEs) hydrolyze the α-1,6 glycosidic bonds in polysaccharides such as starch, amylopectin, pullulan and glycogen. SDBEs are also important enzymes for the preparation of sugar syrup, resistant starch and cyclodextrin. As the synergistic catalysis of SDBEs and other starch-acting hydrolases can effectively improve the raw material utilization and production efficiency during starch processing steps such as saccharification and modification, they have attracted substantial research interest in the past decades. The substrate specificities of the two major members of SDBEs, pullulanases and isoamylases, are quite different. Pullulanases generally require at least two α-1,4 linked glucose units existing on both sugar chains linked by the α-1,6 bond, while isoamylases require at least three units of α-1,4 linked glucose. SDBEs mainly belong to glycoside hydrolase (GH) family 13 and 57. Except for GH57 type II pullulanse, GH13 pullulanases and isoamylases share plenty of similarities in sequence and structure of the core catalytic domains. However, the N-terminal domains, which might be one of the determinants contributing to the substrate binding of SDBEs, are distinct in different enzymes. In order to overcome the current defects of SDBEs in catalytic efficiency, thermostability and expression level, great efforts have been made to develop effective enzyme engineering and fermentation strategies. Herein, the diverse biochemical properties and distinct features in the sequence and structure of pullulanase and isoamylase from different sources are summarized. Up-to-date developments in the enzyme engineering, heterologous production and industrial applications of SDBEs is also reviewed. Finally, research perspective which could help understanding and broadening the applications of SDBEs are provided.
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Gene cloning, expression and biochemical characterization of a new multi-domain, halotolerant and SDS-resistant alkaline pullulanase from Alkalibacterium sp. SL3. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.05.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Chen P, Liu R, Huang M, Zhu J, Wei D, Castellino FJ, Dang G, Xie F, Li G, Cui Z, Liu S, Zhang Y. A unique combination of glycoside hydrolases in Streptococcus suis specifically and sequentially acts on host-derived αGal-epitope glycans. J Biol Chem 2020; 295:10638-10652. [PMID: 32518157 DOI: 10.1074/jbc.ra119.011977] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 06/06/2020] [Indexed: 01/02/2023] Open
Abstract
Infections by many bacterial pathogens rely on their ability to degrade host glycans by producing glycoside hydrolases (GHs). Here, we discovered a conserved multifunctional GH, SsGalNagA, containing a unique combination of two family 32 carbohydrate-binding modules (CBM), a GH16 domain and a GH20 domain, in the zoonotic pathogen Streptococcus suis 05ZYH33. Enzymatic assays revealed that the SsCBM-GH16 domain displays endo-(β1,4)-galactosidase activity specifically toward the host-derived αGal epitope Gal(α1,3)Gal(β1,4)Glc(NAc)-R, whereas the SsGH20 domain has a wide spectrum of exo-β-N-acetylhexosaminidase activities, including exo-(β1,3)-N-acetylglucosaminidase activity, and employs this activity to act in tandem with SsCBM-GH16 on the αGal-epitope glycan. Further, we found that the CBM32 domain adjacent to the SsGH16 domain is indispensable for SsGH16 catalytic activity. Surface plasmon resonance experiments uncovered that both CBM32 domains specifically bind to αGal-epitope glycan, and together they had a KD of 3.5 mm toward a pentasaccharide αGal-epitope glycan. Cell-binding and αGal epitope removal assays revealed that SsGalNagA efficiently binds to both swine erythrocytes and tracheal epithelial cells and removes the αGal epitope from these cells, suggesting that SsGalNagA functions in nutrient acquisition or alters host signaling in S. suis Both binding and removal activities were blocked by an αGal-epitope glycan. SsGalNagA is the first enzyme reported to sequentially act on a glycan containing the αGal epitope. These findings shed detailed light on the evolution of GHs and an important host-pathogen interaction.
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Affiliation(s)
- Ping Chen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ran Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Mengmeng Huang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jinlu Zhu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Dong Wei
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Francis J Castellino
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA.,W. M. Keck Center for Transgene Research, University of Notre Dame, Notre Dame, Indiana, USA
| | - Guanghui Dang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Fang Xie
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Gang Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ziyin Cui
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Siguo Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yueling Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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Huang P, Wu S, Yang S, Yan Q, Jiang Z. Structural basis of carbohydrate binding in domain C of a type I pullulanase fromPaenibacillus barengoltzii. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2020; 76:447-457. [DOI: 10.1107/s205979832000409x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 03/24/2020] [Indexed: 11/10/2022]
Abstract
Pullulanase (EC 3.2.1.41) is a well known starch-debranching enzyme that catalyzes the cleavage of α-1,6-glycosidic linkages in α-glucans such as starch and pullulan. Crystal structures of a type I pullulanase fromPaenibacillus barengoltzii(PbPulA) and ofPbPulA in complex with maltopentaose (G5), maltohexaose (G6)/α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) were determined in order to better understand substrate binding to this enzyme.PbPulA belongs to glycoside hydrolase (GH) family 13 subfamily 14 and is composed of three domains (CBM48, A and C). Three carbohydrate-binding sites identified inPbPulA were located in CBM48, near the active site and in domain C, respectively. The binding site in CBM48 was specific for β-CD, while that in domain C has not been reported for other pullulanases. The domain C binding site had higher affinity for α-CD than for G6; a small motif (FGGEH) seemed to be one of the major determinants for carbohydrate binding in this domain. Structure-based mutations of several surface-exposed aromatic residues in CBM48 and domain C had a debilitating effect on the activity of the enzyme. These results suggest that both CBM48 and domain C play a role in binding substrates. The crystal forms described contribute to the understanding of pullulanase domain–carbohydrate interactions.
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Carrillo JB, Torresi F, Morales LL, Ricordi M, Gomez-Casati DF, Busi MV, Martín M. Identification and characterization of ChlreSEX4, a novel glucan phosphatase from Chlamydomonas reinhardtii green alga. Arch Biochem Biophys 2020; 680:108235. [PMID: 31877265 DOI: 10.1016/j.abb.2019.108235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/18/2019] [Accepted: 12/20/2019] [Indexed: 11/16/2022]
Abstract
Chlamydomonas reinhardtii is the best known unicellular green alga model which has long been used to investigate all kinds of cellular processes, including starch metabolism. Here we identified and characterized a novel enzyme, ChlreSEX4, orthologous to glucan phosphatase SEX4 from Arabidopsis thaliana, that is capable of binding and dephosphorylating amylopectin in vitro. We also reported that cysteine 224 and tryptophan 305 residues are critical for enzyme catalysis and substrate binding. Furthermore, we verified that ChlreSEX4 gene is expressed in vivo and that glucan phosphatase activity is measurable in Chlamydomonas protein extracts. In view of the results presented, we suggest ChlreSEX4 as a functional phosphoglucan phosphatase from C. reinhardtii. Our data obtained so far contribute to understanding the phosphoglucan phosphatases evolutionary process in the green lineage and their role in starch reversible phosphorylation. In addition, this allows to position Chlamydomonas as a potential tool to obtain starches with different degrees of phosphorylation for industrial or biotechnological purposes.
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Affiliation(s)
- Julieta B Carrillo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Florencia Torresi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Luisina L Morales
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Micaela Ricordi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Diego F Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Maria V Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina.
| | - Mariana Martín
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina.
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11
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Andersen S, Svensson B, Møller MS. Roles of the N-terminal domain and remote substrate binding subsites in activity of the debranching barley limit dextrinase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140294. [DOI: 10.1016/j.bbapap.2019.140294] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/15/2019] [Accepted: 10/10/2019] [Indexed: 11/28/2022]
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12
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Janeček Š, Mareček F, MacGregor EA, Svensson B. Starch-binding domains as CBM families-history, occurrence, structure, function and evolution. Biotechnol Adv 2019; 37:107451. [PMID: 31536775 DOI: 10.1016/j.biotechadv.2019.107451] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/01/2019] [Accepted: 09/15/2019] [Indexed: 01/05/2023]
Abstract
The term "starch-binding domain" (SBD) has been applied to a domain within an amylolytic enzyme that gave the enzyme the ability to bind onto raw, i.e. thermally untreated, granular starch. An SBD is a special case of a carbohydrate-binding domain, which in general, is a structurally and functionally independent protein module exhibiting no enzymatic activity but possessing potential to target the catalytic domain to the carbohydrate substrate to accommodate it and process it at the active site. As so-called families, SBDs together with other carbohydrate-binding modules (CBMs) have become an integral part of the CAZy database (http://www.cazy.org/). The first two well-described SBDs, i.e. the C-terminal Aspergillus-type and the N-terminal Rhizopus-type have been assigned the families CBM20 and CBM21, respectively. Currently, among the 85 established CBM families in CAZy, fifteen can be considered as families having SBD functional characteristics: CBM20, 21, 25, 26, 34, 41, 45, 48, 53, 58, 68, 69, 74, 82 and 83. All known SBDs, with the exception of the extra long CBM74, were recognized as a module consisting of approximately 100 residues, adopting a β-sandwich fold and possessing at least one carbohydrate-binding site. The present review aims to deliver and describe: (i) the SBD identification in different amylolytic and related enzymes (e.g., CAZy GH families) as well as in other relevant enzymes and proteins (e.g., laforin, the β-subunit of AMPK, and others); (ii) information on the position in the polypeptide chain and the number of SBD copies and their CBM family affiliation (if appropriate); (iii) structure/function studies of SBDs with a special focus on solved tertiary structures, in particular, as complexes with α-glucan ligands; and (iv) the evolutionary relationships of SBDs in a tree common to all SBD CBM families (except for the extra long CBM74). Finally, some special cases and novel potential SBDs are also introduced.
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Affiliation(s)
- Štefan Janeček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia; Department of Biology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia.
| | - Filip Mareček
- Laboratory of Protein Evolution, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, SK-84551 Bratislava, Slovakia; Department of Biology, Faculty of Natural Sciences, University of SS. Cyril and Methodius, Nám. J. Herdu 2, SK-91701 Trnava, Slovakia
| | - E Ann MacGregor
- 2 Nicklaus Green, Livingston EH54 8RX, West Lothian, United Kingdom
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
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Jiao Y, Wu Y, Chen H, Wang S, Chen L, Lv M, Fang Y, Liu S. The impact of N-terminal nonessential domains on the enzymological properties of the pullulanase from a marine Bacillus megaterium. Biotechnol Lett 2019; 41:849-857. [DOI: 10.1007/s10529-019-02686-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/02/2019] [Indexed: 12/14/2022]
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14
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Wang X, Nie Y, Xu Y. Industrially produced pullulanases with thermostability: Discovery, engineering, and heterologous expression. BIORESOURCE TECHNOLOGY 2019; 278:360-371. [PMID: 30709762 DOI: 10.1016/j.biortech.2019.01.098] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Pullulanases (EC 3.2.1.41) are well-known starch-debranching enzymes widely used to hydrolyze α-1,6-glucosidic linkages in starch, pullulan, amylopectin, and other oligosaccharides, with application potentials in food, brewing, and pharmaceutical industries. Although extensive studies are done to discover and express pullulanases, only few are available with desirable characteristics for industrial applications. This raises the challenge to mine new enzyme sources, engineer proteins based on sequence/structure, and regulate expressions. We review here the identification of extremophilic and mesophilic microbes as sources of industrial pullulanases with desirable characteristics, including acid-resistance, thermostability, and psychrotrophism. We present current advances in site-directed mutagenesis and sequence/structure-guided protein engineering of pullulanases. In addition, we discuss heterologous expression of pullulanases in prokaryotic and eukaryotic microbial systems, and address the effectiveness of the expression elements and their regulation of enzyme production. Finally, we indicate future research needs to develop desired industrial pullulanases.
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Affiliation(s)
- Xinye Wang
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Yao Nie
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China.
| | - Yan Xu
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; The 2011 Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 214122, China.
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15
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Klontz EH, Trastoy B, Deredge D, Fields JK, Li C, Orwenyo J, Marina A, Beadenkopf R, Günther S, Flores J, Wintrode PL, Wang LX, Guerin ME, Sundberg EJ. Molecular Basis of Broad Spectrum N-Glycan Specificity and Processing of Therapeutic IgG Monoclonal Antibodies by Endoglycosidase S2. ACS CENTRAL SCIENCE 2019; 5:524-538. [PMID: 30937380 PMCID: PMC6439443 DOI: 10.1021/acscentsci.8b00917] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Indexed: 06/02/2023]
Abstract
Immunoglobulin G (IgG) glycosylation critically modulates antibody effector functions. Streptococcus pyogenes secretes a unique endo-β-N-acetylglucosaminidase, EndoS2, which deglycosylates the conserved N-linked glycan at Asn297 on IgG Fc to eliminate its effector functions and evade the immune system. EndoS2 and specific point mutants have been used to chemoenzymatically synthesize antibodies with customizable glycosylation for gain of functions. EndoS2 is useful in these schemes because it accommodates a broad range of N-glycans, including high-mannose, complex, and hybrid types; however, its mechanism of substrate recognition is poorly understood. We present crystal structures of EndoS2 alone and bound to complex and high-mannose glycans; the broad N-glycan specificity is governed by critical loops that shape the binding site of EndoS2. Furthermore, hydrolytic experiments, domain-swap chimeras, and hydrogen-deuterium exchange mass spectrometry reveal the importance of the carbohydrate-binding module in the mechanism of IgG recognition by EndoS2, providing insights into engineering enzymes to catalyze customizable glycosylation reactions.
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Affiliation(s)
- Erik H. Klontz
- Institute
of Human Virology, Department of Microbiology & Immunology, and Program in Molecular
Microbiology & Immunology, University
of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Beatriz Trastoy
- Structural
Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Daniel Deredge
- Department
of Pharmaceutical Sciences, University of
Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - James K. Fields
- Institute
of Human Virology, Department of Microbiology & Immunology, and Program in Molecular
Microbiology & Immunology, University
of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Chao Li
- Department
of Chemistry and Biochemistry, University
of Maryland, College Park, Maryland 20742, United States
| | - Jared Orwenyo
- Department
of Chemistry and Biochemistry, University
of Maryland, College Park, Maryland 20742, United States
| | - Alberto Marina
- Structural
Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Robert Beadenkopf
- Institute
of Human Virology, Department of Microbiology & Immunology, and Program in Molecular
Microbiology & Immunology, University
of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Sebastian Günther
- Institute
of Human Virology, Department of Microbiology & Immunology, and Program in Molecular
Microbiology & Immunology, University
of Maryland School of Medicine, Baltimore, Maryland 21201, United States
- Photon
Science, Deutsches Elektronen-Synchrotron, Hamburg 22607, Germany
| | - Jair Flores
- Institute
of Human Virology, Department of Microbiology & Immunology, and Program in Molecular
Microbiology & Immunology, University
of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Patrick L. Wintrode
- Department
of Pharmaceutical Sciences, University of
Maryland School of Pharmacy, Baltimore, Maryland 21201, United States
| | - Lai-Xi Wang
- Department
of Chemistry and Biochemistry, University
of Maryland, College Park, Maryland 20742, United States
| | - Marcelo E. Guerin
- Structural
Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
- IKERBASQUE,
Basque Foundation for Science, 48013 Bilbao, Spain
| | - Eric J. Sundberg
- Institute
of Human Virology, Department of Microbiology & Immunology, and Program in Molecular
Microbiology & Immunology, University
of Maryland School of Medicine, Baltimore, Maryland 21201, United States
- Department
of Medicine, University of Maryland School
of Medicine, Baltimore, Maryland 21201, United States
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16
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Wilkens C, Svensson B, Møller MS. Functional Roles of Starch Binding Domains and Surface Binding Sites in Enzymes Involved in Starch Biosynthesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1652. [PMID: 30483298 PMCID: PMC6243121 DOI: 10.3389/fpls.2018.01652] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/24/2018] [Indexed: 05/07/2023]
Abstract
Biosynthesis of starch is catalyzed by a cascade of enzymes. The activity of a large number of these enzymes depends on interaction with polymeric substrates via carbohydrate binding sites, which are situated outside of the catalytic site and its immediate surroundings including the substrate-binding crevice. Such secondary binding sites can belong to distinct starch binding domains (SBDs), classified as carbohydrate binding modules (CBMs), or be surface binding sites (SBSs) exposed on the surface of catalytic domains. Currently in the Carbohydrate-Active enZYmes (CAZy) database SBDs are found in 13 CBM families. Four of these families; CBM20, CBM45, CBM48, and CBM53 are represented in enzymes involved in starch biosynthesis, namely starch synthases, branching enzymes, isoamylases, glucan, water dikinases, and α-glucan phosphatases. A critical role of the SBD in activity has not been demonstrated for any of these enzymes. Among the well-characterized SBDs important for starch biosynthesis are three CBM53s of Arabidopsis thaliana starch synthase III, which have modest affinity. SBSs, which are overall less widespread than SBDs, have been reported in some branching enzymes, isoamylases, synthases, phosphatases, and phosphorylases active in starch biosynthesis. SBSs appear to exert roles similar to CBMs. SBSs, however, have also been shown to modulate specificity for example by discriminating the length of chains transferred by branching enzymes. Notably, the difference in rate of occurrence between SBDs and SBSs may be due to lack of awareness of SBSs. Thus, SBSs as opposed to CBMs are not recognized at the protein sequence level, which hampers their identification. Moreover, only a few SBSs in enzymes involved in starch biosynthesis have been functionally characterized, typically by structure-guided site-directed mutagenesis. The glucan phosphatase Like SEX4 2 from A. thaliana has two SBSs with weak affinity for β-cyclodextrin, amylose and amylopectin, which were indicated by mutational analysis to be more important than the active site for initial substrate recognition. The present review provides an update on occurrence of functional SBDs and SBSs in enzymes involved in starch biosynthesis.
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Affiliation(s)
- Casper Wilkens
- Enzyme Technology, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Marie Sofie Møller
- Enzyme and Protein Chemistry, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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17
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Saka N, Iwamoto H, Malle D, Takahashi N, Mizutani K, Mikami B. Elucidation of the mechanism of interaction between Klebsiella pneumoniae pullulanase and cyclodextrin. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:1115-1123. [DOI: 10.1107/s2059798318014523] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 10/15/2018] [Indexed: 11/10/2022]
Abstract
Crystal structures of Klebsiella pneumoniae pullulanase (KPP) in complex with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD) and γ-cyclodextrin (γ-CD) were refined at around 1.98–2.59 Å resolution from data collected at SPring-8. In the structures of the complexes obtained with 1 mM α-CD or γ-CD, one molecule of CD was found at carbohydrate-binding module 41 only (CBM41). In the structures of the complexes obtained with 1 mM β-CD or with 10 mM α-CD or γ-CD, two molecules of CD were found at CBM41 and in the active-site cleft, where the hydrophobic residue of Phe746 occupies the inside cavity of the CD rings. In contrast to α-CD and γ-CD, one β-CD molecule was found at the active site only in the presence of 0.1 mM β-CD. These results were coincident with the solution experiments, which showed that β-CD inhibits this enzyme more than a thousand times more potently than α-CD and γ-CD. The strong inhibition of β-CD is caused by the optimized interaction between β-CD and the side chain of Phe746. The increased K
i values of the F746A mutant for β-CD supported the importance of Phe746 in the strong interaction of pullulanase with β-CD.
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18
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Lyu Q, Zhang K, Zhu Q, Li Z, Liu Y, Fitzek E, Yohe T, Zhao L, Li W, Liu T, Yin Y, Liu W. Structural and biochemical characterization of a multidomain alginate lyase reveals a novel role of CBM32 in CAZymes. Biochim Biophys Acta Gen Subj 2018; 1862:1862-1869. [DOI: 10.1016/j.bbagen.2018.05.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 01/27/2023]
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19
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Hobbs JK, Pluvinage B, Boraston AB. Glycan-metabolizing enzymes in microbe-host interactions: the Streptococcus pneumoniae paradigm. FEBS Lett 2018; 592:3865-3897. [PMID: 29608212 DOI: 10.1002/1873-3468.13045] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 12/31/2022]
Abstract
Streptococcus pneumoniae is a frequent colonizer of the upper airways; however, it is also an accomplished pathogen capable of causing life-threatening diseases. To colonize and cause invasive disease, this bacterium relies on a complex array of factors to mediate the host-bacterium interaction. The respiratory tract is rich in functionally important glycoconjugates that display a vast range of glycans, and, thus, a key component of the pneumococcus-host interaction involves an arsenal of bacterial carbohydrate-active enzymes to depolymerize these glycans and carbohydrate transporters to import the products. Through the destruction of host glycans, the glycan-specific metabolic machinery deployed by S. pneumoniae plays a variety of roles in the host-pathogen interaction. Here, we review the processing and metabolism of the major host-derived glycans, including N- and O-linked glycans, Lewis and blood group antigens, proteoglycans, and glycogen, as well as some dietary glycans. We discuss the role of these metabolic pathways in the S. pneumoniae-host interaction, speculate on the potential of key enzymes within these pathways as therapeutic targets, and relate S. pneumoniae as a model system to glycan processing in other microbial pathogens.
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Affiliation(s)
- Joanne K Hobbs
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
| | - Benjamin Pluvinage
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
| | - Alisdair B Boraston
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
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20
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An Extracellular Cell-Attached Pullulanase Confers Branched α-Glucan Utilization in Human Gut Lactobacillus acidophilus. Appl Environ Microbiol 2017; 83:AEM.00402-17. [PMID: 28411221 DOI: 10.1128/aem.00402-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/06/2017] [Indexed: 12/16/2022] Open
Abstract
Of the few predicted extracellular glycan-active enzymes, glycoside hydrolase family 13 subfamily 14 (GH13_14) pullulanases are the most common in human gut lactobacilli. These enzymes share a unique modular organization, not observed in other bacteria, featuring a catalytic module, two starch binding modules, a domain of unknown function, and a C-terminal surface layer association protein (SLAP) domain. Here, we explore the specificity of a representative of this group of pullulanases, Lactobacillus acidophilus Pul13_14 (LaPul13_14), and its role in branched α-glucan metabolism in the well-characterized Lactobacillus acidophilus NCFM, which is widely used as a probiotic. Growth experiments with L. acidophilus NCFM on starch-derived branched substrates revealed a preference for α-glucans with short branches of about two to three glucosyl moieties over amylopectin with longer branches. Cell-attached debranching activity was measurable in the presence of α-glucans but was repressed by glucose. The debranching activity is conferred exclusively by LaPul13_14 and is abolished in a mutant strain lacking a functional LaPul13_14 gene. Hydrolysis kinetics of recombinant LaPul13_14 confirmed the preference for short-branched α-glucan oligomers consistent with the growth data. Curiously, this enzyme displayed the highest catalytic efficiency and the lowest Km reported for a pullulanase. Inhibition kinetics revealed mixed inhibition by β-cyclodextrin, suggesting the presence of additional glucan binding sites besides the active site of the enzyme, which may contribute to the unprecedented substrate affinity. The enzyme also displays high thermostability and higher activity in the acidic pH range, reflecting adaptation to the physiologically challenging conditions in the human gut.IMPORTANCE Starch is one of the most abundant glycans in the human diet. Branched α-1,6-glucans in dietary starch and glycogen are nondegradable by human enzymes and constitute a metabolic resource for the gut microbiota. The role of health-beneficial lactobacilli prevalent in the human small intestine in starch metabolism remains unexplored in contrast to colonic bacterial residents. This study highlights the pivotal role of debranching enzymes in the breakdown of starchy branched α-glucan oligomers (α-limit dextrins) by human gut lactobacilli exemplified by Lactobacillus acidophilus NCFM, which is one of the best-characterized strains used as probiotics. Our data bring novel insight into the metabolic preference of L. acidophilus for α-glucans with short α-1,6-branches. The unprecedented affinity of the debranching enzyme that confers growth on these substrates reflects its adaptation to the nutrient-competitive gut ecological niche and constitutes a potential advantage in cross-feeding from human and bacterial dietary starch metabolism.
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21
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Janeček Š, Majzlová K, Svensson B, MacGregor EA. The starch-binding domain family CBM41-Anin silicoanalysis of evolutionary relationships. Proteins 2017; 85:1480-1492. [DOI: 10.1002/prot.25309] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 04/05/2017] [Accepted: 04/17/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Štefan Janeček
- Institute of Molecular Biology, Slovak Academy of Sciences; Bratislava Slovakia
- Department of Biology; Faculty of Natural Sciences, University of SS. Cyril and Methodius; Trnava Slovakia
| | - Katarína Majzlová
- Institute of Molecular Biology, Slovak Academy of Sciences; Bratislava Slovakia
| | - Birte Svensson
- Department of Biotechnology and Biomedicine; Technical University of Denmark; Kgs. Lyngby Denmark
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22
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Czjzek M, Ficko-Blean E. Probing the Complex Architecture of Multimodular Carbohydrate-Active Enzymes Using a Combination of Small Angle X-Ray Scattering and X-Ray Crystallography. Methods Mol Biol 2017; 1588:239-253. [PMID: 28417374 DOI: 10.1007/978-1-4939-6899-2_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The various modules in multimodular carbohydrate-active enzymes (CAZymes) may function in catalysis, carbohydrate binding, protein-protein interactions or as linkers. Here, we describe how combining the biophysical techniques of Small Angle X-ray Scattering (SAXS) and macromolecular X-ray crystallography (XRC) provides a powerful tool for examination into questions related to overall structural organization of ultra multimodular CAZymes.
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Affiliation(s)
- Mirjam Czjzek
- UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Sorbonne Universite, Station Biologique de Roscoff, Place Georges Teissier, 29688, Roscoff, Bretagne, France.
| | - Elizabeth Ficko-Blean
- UPMC Univ Paris 06, CNRS, UMR 8227, Integrative Biology of Marine Models, Sorbonne Universite, Station Biologique de Roscoff, Place Georges Teissier, 29688, Roscoff, Bretagne, France.
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23
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Cockburn DW, Koropatkin NM. Polysaccharide Degradation by the Intestinal Microbiota and Its Influence on Human Health and Disease. J Mol Biol 2016; 428:3230-3252. [PMID: 27393306 DOI: 10.1016/j.jmb.2016.06.021] [Citation(s) in RCA: 320] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 02/06/2023]
Abstract
Carbohydrates comprise a large fraction of the typical diet, yet humans are only able to directly process some types of starch and simple sugars. The remainder transits the large intestine where it becomes food for the commensal bacterial community. This is an environment of not only intense competition but also impressive cooperation for available glycans, as these bacteria work to maximize their energy harvest from these carbohydrates during their limited transit time through the gut. The species within the gut microbiota use a variety of strategies to process and scavenge both dietary and host-produced glycans such as mucins. Some act as generalists that are able to degrade a wide range of polysaccharides, while others are specialists that are only able to target a few select glycans. All are members of a metabolic network where substantial cross-feeding takes place, as by-products of one organism serve as important resources for another. Much of this metabolic activity influences host physiology, as secondary metabolites and fermentation end products are absorbed either by the epithelial layer or by transit via the portal vein to the liver where they can have additional effects. These microbially derived compounds influence cell proliferation and apoptosis, modulate the immune response, and can alter host metabolism. This review summarizes the molecular underpinnings of these polysaccharide degradation processes, their impact on human health, and how we can manipulate them through the use of prebiotics.
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Affiliation(s)
- Darrell W Cockburn
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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24
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Møller MS, Henriksen A, Svensson B. Structure and function of α-glucan debranching enzymes. Cell Mol Life Sci 2016; 73:2619-41. [PMID: 27137180 PMCID: PMC11108273 DOI: 10.1007/s00018-016-2241-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 10/21/2022]
Abstract
α-Glucan debranching enzymes hydrolyse α-1,6-linkages in starch/glycogen, thereby, playing a central role in energy metabolism in all living organisms. They belong to glycoside hydrolase families GH13 and GH57 and several of these enzymes are industrially important. Nine GH13 subfamilies include α-glucan debranching enzymes; isoamylase and glycogen debranching enzymes (GH13_11); pullulanase type I/limit dextrinase (GH13_12-14); pullulan hydrolase (GH13_20); bifunctional glycogen debranching enzyme (GH13_25); oligo-1 and glucan-1,6-α-glucosidases (GH13_31); pullulanase type II (GH13_39); and α-amylase domains (GH13_41) in two-domain amylase-pullulanases. GH57 harbours type II pullulanases. Specificity differences, domain organisation, carbohydrate binding modules, sequence motifs, three-dimensional structures and specificity determinants are discussed. The phylogenetic analysis indicated that GH13_39 enzymes could represent a "missing link" between the strictly α-1,6-specific debranching enzymes and the enzymes with dual specificity and α-1,4-linkage preference.
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Affiliation(s)
- Marie Sofie Møller
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
- Center for Molecular Protein Science, Department of Chemistry, Lund University, 221 00, Lund, Sweden.
| | - Anette Henriksen
- Global Research Unit, Department of Large Protein Biophysics and Formulation, Novo Nordisk A/S, Novo Nordisk Park, 2760, Måløv, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
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25
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Molecular characterization of a family 5 glycoside hydrolase suggests an induced-fit enzymatic mechanism. Sci Rep 2016; 6:23473. [PMID: 27032335 PMCID: PMC4817029 DOI: 10.1038/srep23473] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/25/2016] [Indexed: 11/25/2022] Open
Abstract
Glycoside hydrolases (GHs) play fundamental roles in the decomposition of lignocellulosic biomaterials. Here, we report the full-length structure of a cellulase from Bacillus licheniformis (BlCel5B), a member of the GH5 subfamily 4 that is entirely dependent on its two ancillary modules (Ig-like module and CBM46) for catalytic activity. Using X-ray crystallography, small-angle X-ray scattering and molecular dynamics simulations, we propose that the C-terminal CBM46 caps the distal N-terminal catalytic domain (CD) to establish a fully functional active site via a combination of large-scale multidomain conformational selection and induced-fit mechanisms. The Ig-like module is pivoting the packing and unpacking motions of CBM46 relative to CD in the assembly of the binding subsite. This is the first example of a multidomain GH relying on large amplitude motions of the CBM46 for assembly of the catalytically competent form of the enzyme.
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26
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Gregg KJ, Suits MDL, Deng L, Vocadlo DJ, Boraston AB. Structural Analysis of a Family 101 Glycoside Hydrolase in Complex with Carbohydrates Reveals Insights into Its Mechanism. J Biol Chem 2015; 290:25657-69. [PMID: 26304114 DOI: 10.1074/jbc.m115.680470] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 11/06/2022] Open
Abstract
O-Linked glycosylation is one of the most abundant post-translational modifications of proteins. Within the secretory pathway of higher eukaryotes, the core of these glycans is frequently an N-acetylgalactosamine residue that is α-linked to serine or threonine residues. Glycoside hydrolases in family 101 are presently the only known enzymes to be able to hydrolyze this glycosidic linkage. Here we determine the high-resolution structures of the catalytic domain comprising a fragment of GH101 from Streptococcus pneumoniae TIGR4, SpGH101, in the absence of carbohydrate, and in complex with reaction products, inhibitor, and substrate analogues. Upon substrate binding, a tryptophan lid (residues 724-WNW-726) closes on the substrate. The closing of this lid fully engages the substrate in the active site with Asp-764 positioned directly beneath C1 of the sugar residue bound within the -1 subsite, consistent with its proposed role as the catalytic nucleophile. In all of the bound forms of the enzyme, however, the proposed catalytic acid/base residue was found to be too distant from the glycosidic oxygen (>4.3 Å) to serve directly as a general catalytic acid/base residue and thereby facilitate cleavage of the glycosidic bond. These same complexes, however, revealed a structurally conserved water molecule positioned between the catalytic acid/base and the glycosidic oxygen. On the basis of these structural observations we propose a new variation of the retaining glycoside hydrolase mechanism wherein the intervening water molecule enables a Grotthuss proton shuttle between Glu-796 and the glycosidic oxygen, permitting this residue to serve as the general acid/base catalytic residue.
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Affiliation(s)
- Katie J Gregg
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6 and
| | - Michael D L Suits
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6 and
| | - Lehua Deng
- the Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - David J Vocadlo
- the Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Alisdair B Boraston
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6 and
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27
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Molecular engineering of cycloisomaltooligosaccharide glucanotransferase from Bacillus circulans T-3040: structural determinants for the reaction product size and reactivity. Biochem J 2015; 467:259-70. [PMID: 25649478 DOI: 10.1042/bj20140860] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cycloisomaltooligosaccharide glucanotransferase (CITase) is a member of glycoside hydrolase family 66 and it produces cycloisomaltooligosaccharides (CIs). Small CIs (CI-7-9) and large CIs (CI-≥10) are designated as oligosaccharide-type CIs (oligo-CIs) and megalosaccharide-type CIs (megalo-CIs) respectively. CITase from Bacillus circulans T-3040 (BcCITase) produces mainly CI-8 with little megalo-CIs. It has two family 35 carbohydrate-binding modules (BcCBM35-1 and BcCBM35-2). BcCBM35-1 is inserted in a catalytic domain of BcCITase and BcCBM35-2 is located at the C-terminal region. Our previous studies suggested that BcCBM35-1 has two substrate-binding sites (B-1 and B-2) [Suzuki et al. (2014) J. Biol. Chem. 289, 12040-12051]. We implemented site-directed mutagenesis of BcCITase to explore the preference for product size on the basis of the 3D structure of BcCITase. Mutational studies provided evidence that B-1 and B-2 contribute to recruiting substrate and maintaining product size respectively. A mutant (mutant-R) with four mutations (F268V, D469Y, A513V and Y515S) produced three times as much megalo-CIs (CI-10-12) and 1.5 times as much total CIs (CI-7-12) as compared with the wild-type (WT) BcCITase. The 3D structure of the substrate-enzyme complex of mutant-R suggested that the modified product size specificity was attributable to the construction of novel substrate-binding sites in the B-2 site of BcCBM35-1 and reactivity was improved by mutation on subsite -3 on the catalytic domain.
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28
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Oligosaccharide and Substrate Binding in the Starch Debranching Enzyme Barley Limit Dextrinase. J Mol Biol 2015; 427:1263-1277. [DOI: 10.1016/j.jmb.2014.12.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 12/20/2014] [Accepted: 12/27/2014] [Indexed: 11/21/2022]
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29
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Abbott DW, van Bueren AL. Using structure to inform carbohydrate binding module function. Curr Opin Struct Biol 2014; 28:32-40. [PMID: 25108190 DOI: 10.1016/j.sbi.2014.07.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/24/2014] [Accepted: 07/16/2014] [Indexed: 10/24/2022]
Abstract
Generally, non-catalytic carbohydrate binding module (CBM) specificity has been shown to parallel the catalytic activity of the carbohydrate active enzyme (CAZyme) module it is appended to. With the rapid expansion in metagenomic sequence space for the potential discovery of new CBMs in addition to the recent emergence of several new CBM families that display diverse binding profiles and novel functions, elucidating the function of these protein modules has become a much more challenging task. This review summarizes several approaches that have been reported for using primary structure to inform CBM specificity and streamlining their biophysical characterization. In addition we discuss general trends in binding site architecture and several newly identified functions for CBMs. Streams of investigation that will facilitate the development and refinement of sequence-based prediction tools are suggested.
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Affiliation(s)
- D Wade Abbott
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, 5403-1st Ave, Lethbridge, AB, Canada T1J4B1.
| | - Alicia Lammerts van Bueren
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen 9747AG, The Netherlands
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30
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Suits MDL, Pluvinage B, Law A, Liu Y, Palma AS, Chai W, Feizi T, Boraston AB. Conformational analysis of the Streptococcus pneumoniae hyaluronate lyase and characterization of its hyaluronan-specific carbohydrate-binding module. J Biol Chem 2014; 289:27264-27277. [PMID: 25100731 PMCID: PMC4175358 DOI: 10.1074/jbc.m114.578435] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
For a subset of pathogenic microorganisms, including Streptococcus pneumoniae, the recognition and degradation of host hyaluronan contributes to bacterial spreading through the extracellular matrix and enhancing access to host cell surfaces. The hyaluronate lyase (Hyl) presented on the surface of S. pneumoniae performs this role. Using glycan microarray screening, affinity electrophoresis, and isothermal titration calorimetry we show that the N-terminal module of Hyl is a hyaluronan-specific carbohydrate-binding module (CBM) and the founding member of CBM family 70. The 1.2 Å resolution x-ray crystal structure of CBM70 revealed it to have a β-sandwich fold, similar to other CBMs. The electrostatic properties of the binding site, which was identified by site-directed mutagenesis, are distinct from other CBMs and complementary to its acidic ligand, hyaluronan. Dynamic light scattering and solution small angle x-ray scattering revealed the full-length Hyl protein to exist as a monomer/dimer mixture in solution. Through a detailed analysis of the small angle x-ray scattering data, we report the pseudoatomic solution structures of the monomer and dimer forms of the full-length multimodular Hyl.
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Affiliation(s)
- Michael D L Suits
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Benjamin Pluvinage
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Adrienne Law
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Yan Liu
- Glycosciences Laboratory, Imperial College London, Burlington Danes Building, Du Cane Road, London W12 0NN, United Kingdom, and
| | - Angelina S Palma
- Glycosciences Laboratory, Imperial College London, Burlington Danes Building, Du Cane Road, London W12 0NN, United Kingdom, and; REQUIMTE, Department of Chemistry, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Wengang Chai
- Glycosciences Laboratory, Imperial College London, Burlington Danes Building, Du Cane Road, London W12 0NN, United Kingdom, and
| | - Ten Feizi
- Glycosciences Laboratory, Imperial College London, Burlington Danes Building, Du Cane Road, London W12 0NN, United Kingdom, and
| | - Alisdair B Boraston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada,.
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31
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Higgins MA, Suits MD, Marsters C, Boraston AB. Structural and Functional Analysis of Fucose-Processing Enzymes from Streptococcus pneumoniae. J Mol Biol 2014; 426:1469-82. [DOI: 10.1016/j.jmb.2013.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 12/02/2013] [Accepted: 12/05/2013] [Indexed: 10/25/2022]
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32
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Pluvinage B, Hehemann JH, Boraston AB. Substrate recognition and hydrolysis by a family 50 exo-β-agarase, Aga50D, from the marine bacterium Saccharophagus degradans. J Biol Chem 2013; 288:28078-88. [PMID: 23921382 DOI: 10.1074/jbc.m113.491068] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The bacteria that metabolize agarose use multiple enzymes of complementary specificities to hydrolyze the glycosidic linkages in agarose, a linear polymer comprising the repeating disaccharide subunit of neoagarobiose (3,6-anhydro-l-galactose-α-(1,3)-d-galactose) that are β-(1,4)-linked. Here we present the crystal structure of a glycoside hydrolase family 50 exo-β-agarase, Aga50D, from the marine microbe Saccharophagus degradans. This enzyme catalyzes a critical step in the metabolism of agarose by S. degradans through cleaving agarose oligomers into neoagarobiose products that can be further processed into monomers. The crystal structure of Aga50D to 1.9 Å resolution reveals a (β/α)8-barrel fold that is elaborated with a β-sandwich domain and extensive loops. The structures of catalytically inactivated Aga50D in complex with non-hydrolyzed neoagarotetraose (2.05 Å resolution) and neoagarooctaose (2.30 Å resolution) provide views of Michaelis complexes for a β-agarase. In these structures, the d-galactose residue in the -1 subsite is distorted into a (1)S3 skew boat conformation. The relative positioning of the putative catalytic residues are most consistent with a retaining catalytic mechanism. Additionally, the neoagarooctaose complex showed that this extended substrate made substantial interactions with the β-sandwich domain, which resembles a carbohydrate-binding module, thus creating additional plus (+) subsites and funneling the polymeric substrate through the tunnel-shaped active site. A synthesis of these results in combination with an additional neoagarobiose product complex suggests a potential exo-processive mode of action of Aga50D on the agarose double helix.
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Affiliation(s)
- Benjamin Pluvinage
- From the Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada and
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33
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Pluvinage B, Chitayat S, Ficko-Blean E, Abbott DW, Kunjachen JM, Grondin J, Spencer HL, Smith SP, Boraston AB. Conformational Analysis of StrH, the Surface-Attached exo-β-d-N-Acetylglucosaminidase from Streptococcus pneumoniae. J Mol Biol 2013; 425:334-49. [DOI: 10.1016/j.jmb.2012.11.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 11/05/2012] [Accepted: 11/06/2012] [Indexed: 12/22/2022]
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34
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Cameron EA, Maynard MA, Smith CJ, Smith TJ, Koropatkin NM, Martens EC. Multidomain Carbohydrate-binding Proteins Involved in Bacteroides thetaiotaomicron Starch Metabolism. J Biol Chem 2012; 287:34614-25. [PMID: 22910908 PMCID: PMC3464567 DOI: 10.1074/jbc.m112.397380] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/10/2012] [Indexed: 12/18/2022] Open
Abstract
Human colonic bacteria are necessary for the digestion of many dietary polysaccharides. The intestinal symbiont Bacteroides thetaiotaomicron uses five outer membrane proteins to bind and degrade starch. Here, we report the x-ray crystallographic structures of SusE and SusF, two outer membrane proteins composed of tandem starch specific carbohydrate-binding modules (CBMs) with no enzymatic activity. Examination of the two CBMs in SusE and three CBMs in SusF reveals subtle differences in the way each binds starch and is reflected in their K(d) values for both high molecular weight starch and small maltooligosaccharides. Thus, each site seems to have a unique starch preference that may enable these proteins to interact with different regions of starch or its breakdown products. Proteins similar to SusE and SusF are encoded in many other polysaccharide utilization loci that are possessed by human gut bacteria in the phylum Bacteroidetes. Thus, these proteins are likely to play an important role in carbohydrate metabolism in these abundant symbiotic species. Understanding structural changes that diversify and adapt related proteins in the human gut microbial community will be critical to understanding the detailed mechanistic roles that they perform in the complex digestive ecosystem.
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Affiliation(s)
- Elizabeth A. Cameron
- From the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Mallory A. Maynard
- From the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Christopher J. Smith
- From the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
| | - Thomas J. Smith
- the Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Nicole M. Koropatkin
- From the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
- the Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Eric C. Martens
- From the Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109 and
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35
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Ficko-Blean E, Boraston AB. Insights into the recognition of the human glycome by microbial carbohydrate-binding modules. Curr Opin Struct Biol 2012; 22:570-7. [PMID: 22858095 DOI: 10.1016/j.sbi.2012.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 07/10/2012] [Indexed: 10/28/2022]
Abstract
Mammalian glycans are often very complex and consequently both commensal bacteria and bacterial pathogens have developed specialized and often elaborate carbohydrate-active enzyme (CAZyme) systems to interact with these sugars. These enzymes are frequently multimodular, with modular functions most often conferring catalysis (glycoside hydrolase catalytic modules) or carbohydrate-binding (carbohydrate-binding modules or CBMs). Structure-function studies of five CBM families are revealing specificities for complex mammalian carbohydrates. Three of these CBM families (32, 47, and 51) show significant structural identity between their β-sandwich folds, suggesting a shared evolutionary precursor, but have divergent binding specificities. The family 40 and 41 CBMs recognize sialic acid and glycogen, respectively, through different modes of sugar binding, though they also adopt all β-structure folds. A structural view of new models generated for complete CAZymes suggests three distinct modes of CBM deployment: (i) formation of the catalytic site, (ii) coordinated catalysis and binding, and (iii) general substrate adherence.
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Affiliation(s)
- Elizabeth Ficko-Blean
- Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8W 3P6, Canada
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36
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Pérez-Dorado I, Galan-Bartual S, Hermoso JA. Pneumococcal surface proteins: when the whole is greater than the sum of its parts. Mol Oral Microbiol 2012; 27:221-45. [PMID: 22759309 DOI: 10.1111/j.2041-1014.2012.00655.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Surface-exposed proteins of pathogenic bacteria are considered as potential virulence factors through their direct contribution to host-pathogen interactions. Four families of surface proteins decorate the cell surface of the human pathogen Streptococcus pneumoniae. Besides lipoproteins and LPXTG proteins, also present in other gram-positive bacteria, the pneumococcus presents the choline-binding protein (CBP) family and the non-classical surface proteins (NCSPs). The CBPs present specific structural features that allow their anchorage to the cell envelope through non-covalent interaction with choline residues of lipoteichoic acid and teichoic acid. NCSP is an umbrella term for less characterized proteins displaying moonlighting functions on the pneumococcal surface that lack a leader peptide and membrane-anchor motif. Considering the unceasing evolution of microbial species under the selective pressure of antibiotic use, detailed understanding of the interaction between pathogen and the host cells is required for the development of novel therapeutic strategies to combat pneumococcal infections. This article reviews recent progress in the investigation of the three-dimensional structures of surface-exposed pneumococcal proteins. The modular nature of some of them produces a great versatility and sophistication of the virulence functions that, in most cases, cannot be deduced by the structural analysis of the isolated modules.
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Affiliation(s)
- I Pérez-Dorado
- Department of Crystallography and Structural Biology, Instituto de Química-Física Rocasolano, CSIC, Madrid, Spain
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37
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Sticking together: glycogen-degrading virulence. Structure 2011; 19:599-600. [PMID: 21565693 DOI: 10.1016/j.str.2011.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In this issue, van Bueren et al. (2011) take us on a journey from a functional link between the host glycogen-degrading properties of SpuA and Streptococcus pneumoniae virulence using cell-based studies, to revealing the structural basis for glycogen recognition and degradation by this S. pneumoniae virulence factor via complementary X-ray crystallography and small-angle X-ray (SAXS) studies.
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38
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Higgins MA, Ficko-Blean E, Meloncelli PJ, Lowary TL, Boraston AB. The overall architecture and receptor binding of pneumococcal carbohydrate-antigen-hydrolyzing enzymes. J Mol Biol 2011; 411:1017-36. [PMID: 21767550 DOI: 10.1016/j.jmb.2011.06.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 06/16/2011] [Accepted: 06/20/2011] [Indexed: 11/19/2022]
Abstract
The TIGR4 and SP3-BS71 strains of Streptococcus pneumoniae each produce family 98 glycoside hydrolases, called Sp4GH98 and Sp3GH98, respectively, which have different modular architectures and substrate specificities. Sp4GH98 degrades the Lewis(Y) antigen and possesses three C-terminal family 47 carbohydrate-binding modules (CBMs) that bind to this substrate. Sp3GH98 degrades the blood group A/B antigens and has two N-terminal family 51 CBMs that are of unknown function. Here, we examine the complex carbohydrate-binding specificity of the family 51 CBMs from Sp3GH98 (referred to as CBM51-1 and CBM51-2), the structural basis of this interaction, and the overall solution conformations of both Sp3GH98 and Sp4GH98, which are shown to be fully secreted proteins. Through glycan microarray binding analysis and isothermal titration calorimetry, CBM51-1 is found to bind specifically to the blood group A/B antigens. However, due to a series of relatively small structural rearrangements that were revealed in structures determined by X-ray crystallography, CBM51-2 appears to be incapable of binding carbohydrates. Analysis of small-angle X-ray scattering data in combination with the available high-resolution X-ray crystal structures of the Sp3GH98 and Sp4GH98 catalytic modules and their CBMs yielded models of the biological solution structures of the full-length enzymes. These studies reveal the complex architectures of the two enzymes and suggest that carbohydrate recognition by the CBMs and the activity of the catalytic modules are not directly coupled.
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Affiliation(s)
- Melanie A Higgins
- Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, Canada V8W 3P6
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